Author Topic: Clutch question  (Read 8215 times)

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Clutch question
« on: February 22, 2012, 11:07:26 am »
My clutch is starting to get low. I'm trying to decide if I need to buy a clutch kit, or If I can just buy the clutch disk and get on with my life. The issue is, The cheapest clutch kit I can find locally is 150. I can get just the disk for 51 and a throwout bearing for 17. So, 68 sounds a lot better than 150. Would you advice against not replacing the pressure plate? Or is it not that big of a deal to use my old pressure plate?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline thirsty

  • Senior Member
  • ****
  • Posts: 1289
    • Suitor's Garage
Re: Clutch question
« Reply #1 on: February 22, 2012, 11:26:44 am »
I've always replaced everything with new while I was in there. I never use re manufactured either. That's too much hassle to not do everything with good quality parts.
Be patient and save up for the good stuff you will not regret it.
Real trucks are built, not bought Build thread

Give me a long enough lever and a place to stand, and I shall move the earth or break this bolt...Whatever, just hold my beer!

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Clutch question
« Reply #2 on: February 22, 2012, 12:26:35 pm »
Well, I was really considering replacing just my throwout bearing until I looked uo the price for just the clutch disk. Would it hurt anything if I didnt replace the pressure plate?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline thirsty

  • Senior Member
  • ****
  • Posts: 1289
    • Suitor's Garage
Re: Clutch question
« Reply #3 on: February 22, 2012, 01:45:20 pm »
Would it hurt anything if I didnt replace the pressure plate?
If yours is in good working condition...no. It is good practice though.

Taking out a sm465 is not something most people want to do very often so everything usually gets replaced while it is out.
I have mixed and matched clutch components before with varied results.
Real trucks are built, not bought Build thread

Give me a long enough lever and a place to stand, and I shall move the earth or break this bolt...Whatever, just hold my beer!

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Clutch question
« Reply #4 on: February 22, 2012, 02:25:25 pm »
Whats wrong with removing the SM465? I find it quite easy. Unscrew the shifter boot, remove the shifter handle, pull the carpet up, unbolt the bolts in the dog house, jack under the tranny, unbolt the cross member from the frame and tranny, drop cross member, unbolt driveshaft, unbolt 4 bolts from tranny to bell housing, lower and slide back the tranny, unbolt bell housing from engine. Not too hard. Probably take me 45 minutes to remove it.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline mpullen66

  • Newbie
  • Posts: 33
  • Newbie
Re: Clutch question
« Reply #5 on: February 22, 2012, 03:04:44 pm »
When I was 16 I had an 80 stepside with 6 cyl and 3spd on the tree. I didn't have much money so I would go to the salvage yard and get a used clutch disk and put it in. I never had a problem. I just got really good and quick at replacing it. LOL. I know its best to replace all that you can but when your in a bind it works.
Mike
1987 LWB,2WD,350,700R4  times 2

Offline zieg85

  • Global Moderator
  • Senior Member
  • ****
  • Posts: 7595
    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: Clutch question
« Reply #6 on: February 22, 2012, 04:00:43 pm »
Whats wrong with removing the SM465? I find it quite easy. Unscrew the shifter boot, remove the shifter handle, pull the carpet up, unbolt the bolts in the dog house, jack under the tranny, unbolt the cross member from the frame and tranny, drop cross member, unbolt driveshaft, unbolt 4 bolts from tranny to bell housing, lower and slide back the tranny, unbolt bell housing from engine. Not too hard. Probably take me 45 minutes to remove it.

I think you have answered your question.  My questions to you is does the clutch let out just off the floor or all the way at the top?  If just off the floor your pressure plate is weak.  Do you have any chatter or vibration as you let the clutch out?  If you do you have hot spots and you should have the flywheel ground.

Personally I would do it right the first time with everything new.  I am dreading it on my 85.  I am pretty sure my center hump is not bolted in, it is part of the floor.  Having to remove anything interior wise except the shifter and boot makes the job a little easier however I may have to loosen the original exhaust system because the trans just can't go straight back as it will hit the floor.  That SM465 is a heavy dude...
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Clutch question
« Reply #7 on: February 22, 2012, 04:04:28 pm »
The clutch is all the way at the top of the pedal, about 1/2-3/4 inch of clutch on the pedal. No shaking or vibration etc. I never rode the clutch or anything dumb. Its just the disk is getting low and the throwout bearing is yelling at me. If i push the pedal all the way to the floor and move my foot off to the side of it it pops right back up.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline zieg85

  • Global Moderator
  • Senior Member
  • ****
  • Posts: 7595
    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: Clutch question
« Reply #8 on: February 22, 2012, 04:24:13 pm »
Check to see if the throw out bearing has worn the clutch fingers that it rides on.  If not just replace what you are wanting.  For the $82 difference though why take the chance unless you really like to wrestle that trans in and out when the pressure plate goes...  My $.02
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline Blazin

  • Blazin new trails!
  • Senior Member
  • ****
  • Posts: 6130
Re: Clutch question
« Reply #9 on: February 22, 2012, 08:26:26 pm »
SOunds to me like $150 is pretty cheap for piece of mind. I wouldn't do just half of it just on principal.
If the disk is worn, and you never rode it then the plate is probably weak, and has let it slip. Every clutch I have replaced over the years in a vehicle that wasn't abused the main problem is the plate, and the bearing. The disk useually still has wear left on it even when the clutch isn't holding good.
Some people are like Slinkies. Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18454
    • http://www.73-87chevytrucks.com
Re: Clutch question
« Reply #10 on: February 22, 2012, 11:01:11 pm »
If it was me I would replace the assembly and I would also pull the flywheel and have it surfaced. 

Offline bake74

  • Senior Member
  • ****
  • Posts: 5871
    • Build Thread
Re: Clutch question
« Reply #11 on: February 23, 2012, 06:40:35 am »
      I am with everyone else on replacing everything.  But when money is tight and you just don't have it and need to get it fixed, replace the 2 items you mentioned.
  But make darn sure you inspect the pressure plate and flywheel very thoroughly, if not and they are damaged your new parts in a very short amount of time will be bad just like the other componets.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Clutch question
« Reply #12 on: February 23, 2012, 05:14:44 pm »
Alright, thanks for the help guys. I'll see how much money I can pull together and I'll try and get the whole kit. Where can I get my flywheel surfaced?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline zieg85

  • Global Moderator
  • Senior Member
  • ****
  • Posts: 7595
    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: Clutch question
« Reply #13 on: February 23, 2012, 05:44:54 pm »
You may have to call around some but any machine shop that has been in business for a while should be able to resurface it.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Clutch question
« Reply #14 on: February 23, 2012, 06:01:10 pm »
Can it be surfaced on a brake lathe?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF